|3x-1|-x=2
⇔|3x-1|=x+2
⇔\(\left[ \begin{array}{l}3x-1=x+2\\3x-1=-x-2\end{array} \right.\)
⇔\(\left[ \begin{array}{}2x=3\\4x=-1\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=\frac{3}{2}\\x=\frac{-1}{4}\end{array} \right.\)
Vậy S={$\frac{3}{2}$;$\frac{-1}{4}$}